In oil reservoirs, the less-dense oil often lies over a layer of water. When production begins, the oil-water interface rises near the well. There are many factors, such as the presence of thief zones or high permeability zones, voids, fractures and water coning which lead to an increase in water production. Similar problems occur with gas production with oil.
Actions by well operators to increase production, such as water flooding, can also lead to undesirable water production. Water flooding can also lead to inconsistent sweeping actions which require increased water injection and production to recover all significant hydrocarbon pockets.
As oil fields in the United States mature, the volumes of produced water requiring disposal have increased significantly. With numerous older and mature oil fields, the growing problem of water production and stricter environmental regulation of water disposal are forcing oil producers to find ways to eliminate water coning/production and conformance control problems. It has been estimated that approximately many billion barrels of water are reinjected just in the United States every year. Any technology that minimizes the amount of water or gas produced in conjunction with the produced oil would have a significant impact on the volume of oil production and on the cost of oil production.
Various attempts have been made to prevent or reduce the volume of water produced during hydrocarbon production. Crosslinked polymer gels and other materials have been strategically injected into the materials surrounding the well. In U.S. Pat. No. 5,503,227, fractures are formed using a hydrojetting tool, and settable cementitous materials or hardenable resinous materials in a liquid form are squeezed into the fracture to form a block for gas flow around a well. However, difficulties in controlling location and consistency of the placement of these materials in fractures effects performance. Further, these materials tend to be squeezed out of the fracture as the fracture closes. The inability to inject these materials in a large area, or to keep them in the fracture or to keep the fracture horizontal for a long distance, effects the time such procedures remain effective.
Thus, there are needs for methods and materials for use in inhibiting and controlling the movement of fluids in materials surrounding wellbores.